/*
    Nintendo/SGI RSP Disassembler

    Written by Ville Linde
*/

//#include "z64.h"
#include <stdarg.h>
#include <stdio.h>
#include "rsp.h"

#define DASMFLAG_SUPPORTED         0x80000000      /* are disassembly flags supported? */
#define DASMFLAG_STEP_OUT          0x40000000      /* this instruction should be the end of a step out sequence */
#define DASMFLAG_STEP_OVER         0x20000000      /* this instruction should be stepped over by setting a breakpoint afterwards */
#define DASMFLAG_OVERINSTMASK      0x18000000      /* number of extra instructions to skip when stepping over */
#define DASMFLAG_OVERINSTSHIFT     27              /* bits to shift after masking to get the value */
#define DASMFLAG_LENGTHMASK        0x0000ffff      /* the low 16-bits contain the actual length */
#define DASMFLAG_STEP_OVER_EXTRA(x) ((x) << DASMFLAG_OVERINSTSHIFT)

static const char *reg[32] =
{
        "0",    "r1",   "r2",   "r3",   "r4",   "r5",   "r6",   "r7",
        "r8",   "r9",   "r10",  "r11",  "r12",  "r13",  "r14",  "r15",
        "r16",  "r17",  "r18",  "r19",  "r20",  "r21",  "r22",  "r23",
        "r24",  "r25",  "r26",  "r27",  "r28",  "r29",  "r30",  "r31"
};

static const char *vreg[32] =
{
        " v0", " v1", " v2", " v3", " v4", " v5", " v6", " v7",
        " v8", " v9", "v10", "v11", "v12", "v13", "v14", "v15",
        "v16", "v17", "v18", "v19", "v20", "v21", "v22", "v23",
        "v24", "v25", "v26", "v27", "v28", "v29", "v30", "v31"
};

static const char *cop0_regs[32] =
{
        "SP_MEM_ADDR",  "SP_DRAM_ADDR",    "SP_RD_LEN",    "SP_WR_LEN",
        "SP_STATUS",    "SP_DMA_FULL",     "SP_DMA_BUSY",  "SP_SEMAPHORE",
        "DPC_START",    "DPC_END",         "DPC_CURRENT",  "DPC_STATUS",
        "DPC_CLOCK",    "DPC_BUFBUSY",     "DPC_PIPEBUSY", "DPC_TMEM",
        "???",          "???",             "???",          "???",
        "???",          "???",             "???",          "???",
        "???",          "???",             "???",          "???",
        "???",          "???",             "???",          "???"
};

static const char *element[16] =
{
        "",           "[???]",      "[00224466]", "[11335577]", "[00004444]", "[11115555]", "[22226666]", "[33337777]",
        "[00000000]", "[11111111]", "[22222222]", "[33333333]", "[44444444]", "[55555555]", "[66666666]", "[77777777]"
};

static const char *element2[16] =
{
        "01234567", "????????", "00224466", "11335577", "00004444", "11115555", "22226666", "33337777",
        "00000000", "11111111", "22222222", "33333333", "44444444", "55555555", "66666666", "77777777"
};

#define INLINE inline
INLINE char *signed_imm16(UINT32 op)
{
        static char temp[10];
        INT16 value = op & 0xffff;

        if (value < 0)
        {
                sprintf(temp, "-$%04x", -value);
        }
        else
        {
                sprintf(temp, "$%04x", value);
        }
        return temp;
}


static char *output;

static void print(const char *fmt, ...)
{
        va_list vl;

        va_start(vl, fmt);
        output += vsprintf(output, fmt, vl);
        va_end(vl);
}

static void disasm_cop0(UINT32 op)
{
        int rt = (op >> 16) & 31;
        int rd = (op >> 11) & 31;

        switch ((op >> 21) & 0x1f)
        {
                case 0x00:      print("mfc0   %s, %s", reg[rt], cop0_regs[rd]); break;
                case 0x04:      print("mtc0   %s, %s", reg[rt], cop0_regs[rd]); break;

                default:        print("??? (COP0)"); break;
        }
}

static void disasm_cop2(UINT32 op)
{
        int rt = (op >> 16) & 31;
        int rd = (op >> 11) & 31;
        int el = (op >> 21) & 0xf;
        int dest = (op >> 6) & 0x1f;
        int s1 = rd;
        int s2 = rt;

        switch ((op >> 21) & 0x1f)
        {
                case 0x00:      print("mfc2   %s, %s[%d]", reg[rt], vreg[rd], dest); break;
                case 0x02:      print("cfc2   %s, FLAG%d", reg[rt], rd); break;
                case 0x04:      print("mtc2   %s, %s[%d]", reg[rt], vreg[rd], dest); break;
                case 0x06:      print("ctc2   %s, FLAG%d", reg[rt], rd); break;

                case 0x10: case 0x11: case 0x12: case 0x13: case 0x14: case 0x15: case 0x16: case 0x17:
                case 0x18: case 0x19: case 0x1a: case 0x1b: case 0x1c: case 0x1d: case 0x1e: case 0x1f:
                {
                        switch (op & 0x3f)
                        {
                                case 0x00:      print("vmulf  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x01:      print("vmulu  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x02:      print("vrndp  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x03:      print("vmulq  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x04:      print("vmudl  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x05:      print("vmudm  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x06:      print("vmudn  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x07:      print("vmudh  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x08:      print("vmacf  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x09:      print("vmacu  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x0a:      print("vrndn  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x0b:      print("vmacq  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x0c:      print("vmadl  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x0d:      print("vmadm  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x0e:      print("vmadn  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x0f:      print("vmadh  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x10:      print("vadd   %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x11:      print("vsub   %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x12:      print("vsut???"); break;
                                case 0x13:      print("vabs   %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x14:      print("vaddc  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x15:      print("vsubc  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;

                                case 0x1d:
                                {
                                        switch (el)
                                        {
                                                case 8:         print("vsaw   %s, ACCUM_H", vreg[dest]); break;
                                                case 9:         print("vsaw   %s, ACCUM_M", vreg[dest]); break;
                                                case 10:        print("vsaw   %s, ACCUM_L", vreg[dest]); break;
                                                default:        print("vsaw   %s, ???", vreg[dest]); break;
                                        }
                                        break;
                                }

                                case 0x20:      print("vlt    %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x21:      print("veq    %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x22:      print("vne    %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x23:      print("vge    %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x24:      print("vcl    %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x25:      print("vch    %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x26:      print("vcr    %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x27:      print("vmrg   %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x28:      print("vand   %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x29:      print("vnand  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x2a:      print("vor    %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x2b:      print("vnor   %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x2c:      print("vxor   %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x2d:      print("vnxor  %s, %s, %s%s", vreg[dest], vreg[s1], vreg[s2], element[el]); break;
                                case 0x30:      print("vrcp   %s[%d], %s[%c]", vreg[dest], s1 & 7, vreg[s2], element2[el][7-(s1 & 7)]); break;
                                case 0x31:      print("vrcpl  %s[%d], %s[%c]", vreg[dest], s1 & 7, vreg[s2], element2[el][7-(s1 & 7)]); break;
                                case 0x32:      print("vrcph  %s[%d], %s[%c]", vreg[dest], s1 & 7, vreg[s2], element2[el][7-(s1 & 7)]); break;
                                case 0x33:      print("vmov   %s[%d], %s[%c]", vreg[dest], s1 & 7, vreg[s2], element2[el][7-(s1 & 7)]); break;
                                case 0x34:      print("vrsq   %s[%d], %s[%c]", vreg[dest], s1 & 7, vreg[s2], element2[el][7-(s1 & 7)]); break;
                                case 0x35:      print("vrsql  %s[%d], %s[%c]", vreg[dest], s1 & 7, vreg[s2], element2[el][7-(s1 & 7)]); break;
                                case 0x36:      print("vrsqh  %s[%d], %s[%c]", vreg[dest], s1 & 7, vreg[s2], element2[el][7-(s1 & 7)]); break;
                                case 0x37:      print("vnop"); break;
                                default:        print("??? (VECTOR OP)"); break;
                        }
                        break;
                }

                default:        print("??? (COP2)"); break;
        }
}

static void disasm_lwc2(UINT32 op)
{
        int dest = (op >> 16) & 0x1f;
        int base = (op >> 21) & 0x1f;
        int del = (op >> 7) & 0xf;
        int offset = (op & 0x7f);
        if (offset & 0x40)
                offset |= 0xffffff80;

        switch ((op >> 11) & 0x1f)
        {
                case 0x00:      print("lbv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 1), reg[base]); break;
                case 0x01:      print("lsv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 2), reg[base]); break;
                case 0x02:      print("llv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 4), reg[base]); break;
                case 0x03:      print("ldv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 8), reg[base]); break;
                case 0x04:      print("lqv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                case 0x05:      print("lrv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                case 0x06:      print("lpv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 8), reg[base]); break;
                case 0x07:      print("luv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 8), reg[base]); break;
                case 0x08:      print("lhv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                case 0x09:      print("lfv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                case 0x0a:      print("lwv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                case 0x0b:      print("ltv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                default:        print("??? (LWC2)"); break;
        }
}

static void disasm_swc2(UINT32 op)
{
        int dest = (op >> 16) & 0x1f;
        int base = (op >> 21) & 0x1f;
        int del = (op >> 7) & 0xf;
        int offset = (op & 0x7f);
        if (offset & 0x40)
                offset |= 0xffffff80;

        switch ((op >> 11) & 0x1f)
        {
                case 0x00:      print("sbv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 1), reg[base]); break;
                case 0x01:      print("ssv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 2), reg[base]); break;
                case 0x02:      print("slv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 4), reg[base]); break;
                case 0x03:      print("sdv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 8), reg[base]); break;
                case 0x04:      print("sqv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                case 0x05:      print("srv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                case 0x06:      print("spv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 8), reg[base]); break;
                case 0x07:      print("suv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 8), reg[base]); break;
                case 0x08:      print("shv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                case 0x09:      print("sfv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                case 0x0a:      print("swv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                case 0x0b:      print("stv    %s[%d], %s(%s)", vreg[dest], del, signed_imm16(offset * 16), reg[base]); break;
                default:        print("??? (SWC2)"); break;
        }
}

offs_t rsp_dasm_one(char *buffer, offs_t pc, UINT32 op)
{
        int rs = (op >> 21) & 31;
        int rt = (op >> 16) & 31;
        int rd = (op >> 11) & 31;
        int shift = (op >> 6) & 31;
        UINT32 flags = 0;

        output = buffer;

        switch (op >> 26)
        {
                case 0x00:              // SPECIAL
                {
                        switch (op & 0x3f)
                        {
                                case 0x00:
                                {
                                        if (op == 0)
                                        {
                                                print("nop");
                                        }
                                        else
                                        {
                                                print("sll    %s, %s, %d", reg[rd], reg[rt], shift);
                                        }
                                        break;
                                }
                                case 0x02:      print("srl    %s, %s, %d", reg[rd], reg[rt], shift); break;
                                case 0x03:      print("sra    %s, %s, %d", reg[rd], reg[rt], shift); break;
                                case 0x04:      print("sllv   %s, %s, %s", reg[rd], reg[rt], reg[rs]); break;
                                case 0x06:      print("srlv   %s, %s, %s", reg[rd], reg[rt], reg[rs]); break;
                                case 0x07:      print("srav   %s, %s, %s", reg[rd], reg[rt], reg[rs]); break;
                                case 0x08:      print("jr     %s", reg[rs]); if (rs == 31) flags = DASMFLAG_STEP_OUT; break;
                                case 0x09:
                                {
                                        if (rd == 31)
                                        {
                                                print("jalr   %s", reg[rs]);
                                        }
                                        else
                                        {
                                                print("jalr   %s, %s", reg[rs], reg[rd]);
                                        }
                                        flags = DASMFLAG_STEP_OVER | DASMFLAG_STEP_OVER_EXTRA(1);
                                        break;
                                }
                                case 0x0d:      print("break"); flags = DASMFLAG_STEP_OVER;     break;
                                case 0x20:      print("add    %s, %s, %s", reg[rd], reg[rs], reg[rt]); break;
                                case 0x21:      print("addu   %s, %s, %s", reg[rd], reg[rs], reg[rt]); break;
                                case 0x22:      print("sub    %s, %s, %s", reg[rd], reg[rs], reg[rt]); break;
                                case 0x23:      print("subu   %s, %s, %s", reg[rd], reg[rs], reg[rt]); break;
                                case 0x24:      print("and    %s, %s, %s", reg[rd], reg[rs], reg[rt]); break;
                                case 0x25:      print("or     %s, %s, %s", reg[rd], reg[rs], reg[rt]); break;
                                case 0x26:      print("xor    %s, %s, %s", reg[rd], reg[rs], reg[rt]); break;
                                case 0x27:      print("nor    %s, %s, %s", reg[rd], reg[rs], reg[rt]); break;
                                case 0x2a:      print("slt    %s, %s, %s", reg[rd], reg[rs], reg[rt]); break;
                                case 0x2b:      print("sltu   %s, %s, %s", reg[rd], reg[rs], reg[rt]); break;

                                default:        print("???"); break;
                        }
                        break;
                }

                case 0x01:              // REGIMM
                {
                        switch ((op >> 16) & 0x1f)
                        {
                                case 0x00:      print("bltz   %s, $%08X", reg[rs], pc + 4 + ((INT16)op << 2)); break;
                                case 0x01:      print("bgez   %s, $%08X", reg[rs], pc + 4 + ((INT16)op << 2)); break;
                                case 0x10:      print("bltzal %s, $%08X", reg[rs], pc + 4 + ((INT16)op << 2)); break;
                                case 0x11:      print("bgezal %s, $%08X", reg[rs], pc + 4 + ((INT16)op << 2)); break;

                                default:        print("???"); break;
                        }
                        break;
                }

                case 0x02:      print("j      $%08X", (op & 0x03ffffff) << 2); break;
                case 0x03:      print("jal    $%08X", (op & 0x03ffffff) << 2); break;
                case 0x04:      print("beq    %s, %s, $%08X", reg[rs], reg[rt], pc + 4 + ((INT16)(op) << 2)); break;
                case 0x05:      print("bne    %s, %s, $%08X", reg[rs], reg[rt], pc + 4 + ((INT16)(op) << 2)); break;
                case 0x06:      print("blez   %s, $%08X", reg[rs], pc + 4 + ((INT16)(op) << 2)); break;
                case 0x07:      print("bgtz   %s, $%08X", reg[rs], pc + 4 + ((INT16)(op) << 2)); break;
                case 0x08:      print("addi   %s, %s, %s", reg[rt], reg[rs], signed_imm16(op)); break;
                case 0x09:      print("addiu  %s, %s, %s", reg[rt], reg[rs], signed_imm16(op)); break;
                case 0x0a:      print("slti   %s, %s, %s", reg[rt], reg[rs], signed_imm16(op)); break;
                case 0x0b:      print("sltiu  %s, %s, %s", reg[rt], reg[rs], signed_imm16(op)); break;
                case 0x0c:      print("andi   %s, %s, $%04X", reg[rt], reg[rs], (UINT16)(op)); break;
                case 0x0d:      print("ori    %s, %s, $%04X", reg[rt], reg[rs], (UINT16)(op)); break;
                case 0x0e:      print("xori   %s, %s, $%04X", reg[rt], reg[rs], (UINT16)(op)); break;
                case 0x0f:      print("lui    %s, %s, $%04X", reg[rt], reg[rs], (UINT16)(op)); break;

                case 0x10:      disasm_cop0(op); break;
                case 0x12:      disasm_cop2(op); break;

                case 0x20:      print("lb     %s, %s(%s)", reg[rt], signed_imm16(op), reg[rs]); break;
                case 0x21:      print("lh     %s, %s(%s)", reg[rt], signed_imm16(op), reg[rs]); break;
                case 0x23:      print("lw     %s, %s(%s)", reg[rt], signed_imm16(op), reg[rs]); break;
                case 0x24:      print("lbu    %s, %s(%s)", reg[rt], signed_imm16(op), reg[rs]); break;
                case 0x25:      print("lhu    %s, %s(%s)", reg[rt], signed_imm16(op), reg[rs]); break;
                case 0x28:      print("sb     %s, %s(%s)", reg[rt], signed_imm16(op), reg[rs]); break;
                case 0x29:      print("sh     %s, %s(%s)", reg[rt], signed_imm16(op), reg[rs]); break;
                case 0x2b:      print("sw     %s, %s(%s)", reg[rt], signed_imm16(op), reg[rs]); break;

                case 0x32:      disasm_lwc2(op); break;
                case 0x3a:      disasm_swc2(op); break;

                default:        print("???"); break;
        }

        return 4 | flags | DASMFLAG_SUPPORTED;
}
